Booting on battery power sends output to external monitor only, and fails with lots of errors

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This is a very weird one: if I boot my notebook on battery power, built-in display (controlled by an AMD iGPU) remains blank as if nothing is happening; however, if I plug an external monitor to the HDMI port wired to the Nvidia dGPU, I can see the boot messages, with lots of errors. After a couple of minutes, both screens go blank and boot stops entirely.

Booting on AC power works flawlessly, with or without an external monitor plugged in.

I’ve read people complaining about Nvidia’s driver messing up displays when fbdev=1 is passed as a kernel parameter (which is indeed the case here). However, what is puzzling me is why being on battery or AC power would matter :exploding_head:

This is what appears on the logs of the failed boot attempt:

dez 08 15:40:04 fedoracosta systemd[1]: Startup finished in 7.800s (firmware) + 2.707s (loader) + 1.250s (kernel) + 4.630s (initrd) + 20.429s (userspace) = 36.817s.

On a normal boot, this is what is logged:

dez 08 16:11:56 fedoracosta systemd[10379]: Startup finished in 316ms.

Anyone has any idea on what could explain this weird behavior?

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Timing is not likely the issue. When on AC power the cpu is able to run at full speed and when on battery it is limited to minimal speed.

There may be additional info in the logs that could show the cause but that one line is not indicative of the issue.

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It makes sense, but I wouldn’t expect a couple of orders of magnitude higher (from milliseconds to 36 seconds)

BTW I am running kernel 6.12.3-200 from Koji with latest beta driver 565.77 from Nvidia